package com.anlu.base;

import javax.security.auth.callback.Callback;
import java.util.concurrent.Callable;
import java.util.concurrent.ExecutionException;

/**
 * AsyncExecutor interface.
 */
public interface AsyncExecutor {
    /**
     * Starts processing of an async task. Returns immediately with async result.
     *
     * @param task task to be executed asynchronously
     * @return async result for the task
     */
   <T> AsyncResult<T> startProcess(Callable<T> task);

    /**
     * Starts processing of an async task. Returns immediately with async result. Executes callback
     * when the task is completed.
     *
     * @param task     task to be executed asynchronously
     * @param callback callback to be executed on task completion
     * @return async result for the task
     */
    <T> AsyncResult<T> startProcess(Callable<T> task, AsyncCallback<T> callback);
    /**
     * Ends processing of an async task. Blocks the current thread if necessary and returns the
     * evaluated value of the completed task.
     *
     * @param asyncResult async result of a task
     * @return evaluated value of the completed task
     * @throws ExecutionException   if execution has failed, containing the root cause
     * @throws InterruptedException if the execution is interrupted
     */
    <T> T endProcess(AsyncResult<T> asyncResult) throws ExecutionException, InterruptedException;;
}
